<!DOCTYPE HTML>
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <title>函数调用</title>
    <script type="text/javascript">
        function contxt() //定义函数
        {
            alert("哈哈，调用函数了!");
        }
    </script>
</head>
<body>
<form>
    <input type="button"  value="点击我" onclick="contxt()" />
</form>
</body>
</html>